see, the thing about fresh fruit is that although people tend to recommend dried fruit for constipation it is quite high in iron, a surfeit of which can cause babies to become, er, constipated. so it's a tricky one. so lots of water or rehydrating is good if you're doing the prune thing.
i think the sweet tooth thing is bullshit, btw. dd loves sweet things but would still rather have cucumber than a biscuit, the little freak.